Hawaiian Seashells

The triton shell has long been used as a trumpet by the Polynesians. My grandmother used this particular triton to call the workers in for lunch from the mud, humidity and backbreaking work of tending to the Taro paddies. When I found this triton, my step grandmother had filled it with floral clay and plastic flowers and thus it sat in a dark corner, dusty, un-loved and unappreciated. Luckily, even as was a young child, I was fascinated by Hawaiian seashells and, as you might imagine, a little begging with Grandpa soon freed this shell from its ignominous fate.

As a child, I used to sit high atop the hills overlooking Palolo Valley and, as I blew that triton, it's sound echoing all across the valley, I thought of what it might have been like back in the days of my grandma, back when shells like this still washed up on the beach. While I no longer torture my neighbors with the echoing sound of its trumpeting (not too often anyhow), this shell has come to symbolize a link back to my true Grandmother and to the life that she lived in taro fields of old Hanalei.

For the early Hawaiians, seashells were a source of food (for example, opihi, pipipi and other wave zone molluscs were and are still commonly eaten), of adornment (cowries or "leho" in particular were strung in leis), of communication (tritons, conches), of lures (for squid) and as a material for fish hooks and weapons. Shells were a central part of Hawaiian life.

However, as it turns out, all shells, including the Triton also play a unique role in the Hawaiian ecosystem. For example, the triton is one of the only predators that keeps the population of crown of thorns starfish under control. When the Triton was over-collected back in the 70's, the crown of thorns starfish population reached unprecedented highs, causing significant damage to the reef, and requiring mass collection of crown of thorns starfish by divers to save the reef. The Triton is now protected by Hawaiian law, prohibiting the collection and sale of these magnificent shells.

Hawaii's shells have evolved across thousands of years into unique variants of their Indo-Pacific relatives, each with its own ecological niche. Some achieve significantly larger size; others are just color variants. Some of the variation in color or size may be due to slightly different diets, perhaps a different sponge or seaweed species than their Indo-Pacific cousins. Still other shells have speciated into unique and wonderful creatures found nowhere else in the world.

Each of these species occupies a unique niche or role in the Hawaiian ecosystem. We discussed the triton above. Other shells, such as the tiny Vexilla prey upon sea urchins. The reef-flat cones such as the Rat Cones and Soldier Cones typically prey on worms, bristleworms included [author's note: if you've ever been stung by a bristleworm, you'd remember it]. The Beck's Cowrie is only found in the bases of slow growing black coral trees. Thus, when you remove a particular species, either the shell or the host that it depends upon (Black coral for instance), the ecological cycle is broken, often exposing the environment to uncontrolled effects within that niche. These effects can be localized or, as with the triton, far ranging.

While the Hawaiian's used shells extensively and, arguably, Hawaii's residents still do to this day, the greatly enlarged population in the islands, the silt from pervasive human habitation and deforestation and the millions of visitors to Hawaii are exerting unprecedented pressure on Hawaii's fragile marine ecosystems. The advent of scuba and related underwater technologies now gives man unprecedented access to the ocean in a way the Hawaiians never did. As a young child, I thought that the bounty of Hawaii's seas was endless and would last forever, no matter what we did. The reefs were covered with cones, cowries, lobster and coral banded shrimp. However, I have watched the seashells grow more and more scarce where they were once bountiful and can only wonder about the impact on the niches that they occupy. Therefore, if you are thinking about collecting Hawaii's shells, try doing it with a camera. Nothing is killed and you can share with your friends. If you must collect, there are often fairly nice dead specimens washed up on the shore, particulary in areas where coral rubble accumulates. And, if you still cannot resist, please do so with restraint.

On this web page, I have tried to capture a few of Hawaii's shells in photograph in the hopes of preserving and sharing their beauty for those of you that cannot visit Hawaii and see them in person and for those of you that remember what Hawaii once was. That being said, it is a bit tough finding photos of Hawaiian shells so, if you have photos you can share, especially of live Hawaiian seashells, please send them along to be added into later updates.

Okay, on with the story. As a child, my favorite genera was always the Cowrie, known for it's bright colors, smooth, worry-free surface and wonderful sheen. In Hawaii, the general name for Cowries is Leho. In old Hawaii, the natives strung the leho on cord and made shell leis that were worn around the neck for adornment, similar to the ones sold today in convenience stores across the state (typically from the Philippines but that is another story again).

Cowries

Many cowries feed on algae, generally at night. In the day, they may be found hiding underneath coral rubble. Other cowries are found in association with specific corals or sponges upon which they feed. The amazing sheen of their shells is maintained by the animal through a thin membrane or mantle which continues to build the shell throughout the the life of the animal and, in most cases, also hides the animal from predators.

On the reef, the cowrie is normally covered by its mantle, enabling it to blend in with the surrounding algae, rocks and coral. The easiest way to spot a cowrie is to look for the glint of reflection off of the small uncovered area between the two sides of the mantle.

Cypraea allisonae; Allison's Cowrie.

Cypraea caputserpentis; Serpent's head cowry. Once very common in shallow tide pools, over -collecting has relegated many of these to deeper water where they are found in holes in the rock.

Cypraea mauritiana: Humpback cowrie; 2 1/2 to 5 inches; Lehoahi; attached to a weight or stone with a hook and used by the Hawaiians to catch octopus; found from high tide mark to 10 ft, usually on black lava rock in high surf areas, feeds on algae at night.

Cypraea tesselata:: 3/4 to 1 1/2 inches; found in deep (50+ft) water under coral rubble; transparent mantle; endemic to Hawaii.

Cypraea tigris f shilderiana: Tiger cowrie; although widespread throughout the Pacific, the Hawaiian form of this corwrie attains size up to around 5 inches. Found in coral caves or ledges.

Cypraea vitellus; Calf Cowrie; 1 1/2 - 2 1/2 inches; found from 2-25 ft under dead coral; rare and attains much larger size in Hawaii. The individual on the left is a typical specimen from the Phillipines and the speciment on the right is from Hawaii.

Cones & Other Hawaiian Seashells

There are many other fascinating shells in Hawaii that fill a broad variety of ecological niches. For example, the Cones are largely carnivorous, feeding on worms, shells, fish and even other cones. On the flip side, the conchs are largely herbivorous, being the cows of the sea, as they patiently graze on algae. A few, such as the marbled top snail (2mm), are so small they are best looked at under a magnifying glass and can often be found as you sift through beach sand.

The cones are carnivores, each capable of delivering a venonous sting that is used to paralyze its prey. The cone then typically envelopes the prey with its proboscis and digests it, discarding the remains. Conus marmoreous is one of three Hawaiian cones notedly poisonous to humans (although all are capable of stinging). This cone preys upon other cone shells. The other two poisonous Hawaiian cones, Conus textile and Conus striatus prey upon other shells and sand gobies (and other small sand-dwelling fish) respectively.

Many of the more common shells also found their way into the Hawaiian diet. The Hawaiian Limpet or Opihi is a favorite to this day and is eaten raw, sometimes right off the rock, or mixed with seaweed and spices (Opihi Limu Poki). The following are a small sample of the multitude of Hawaiian shells.

Cellana sandwicensis: One of three species of Hawaiian Limpets or Opihi; eaten raw as a Hawaiian delicacy. found in the splash zone on exposed lava rock; once very common but heavy collecting has led to smaller sizes and decreased populations, typically in less accessable areas with large surf.

Charonia tritonis; Pu or Ole; Triton's trumpet; found from 40-130 ft on coral ledges or in coral caves; rare; a serious carnivore that feeds on starfish, mollusks and worms; when used as a horn, it can be heard for miles.

Conus bandanus or Conus marmoreus var bandanus; poisonous stinger; lives on other cone shells; up to 5 inches; found in reef rubble from 5-60 ft.

Conus bullatus; Bubble Cone; up to about 4 inches; found in deep water (50+ft) in sand and coral rubble.

Conus striatus; Striated cone; poisonous; found burried under sand from 15-60ft; feeds on gobies and other sand-loving fish, which it stings, paralyzes, envelops and digests

Conus textile; Textile Cone or Cloth of Gold Cone; feeds on other shells; found from 15-90 ft under sand or coral rubble; poisonous.

Mitra auriculoides; up to 1 inch; from shallow water to 15 feet in rock or coral chunks.

Hydatina amplustre: Swollen Bubble; up to about an inch but usually considerably smaller; found buried in sand in shallow water.

Mitra papalis: Papal Miter; up to 6 inches; from 30-80 ft under coral, a venomous carnivore that feeds on worms and invertebrates.

Drupa nodus (Knobbed Drupe) or Morula uva (grape drupe): found in tidal zone and on rocks splashed by waves.

Murex pele or Homolocantha anatomica: Pele's Murex; the Hawaiian variant of Homolocantha anatomica is found in a wide variety of colors including white, purple, orange and yellow. Typically found in deep water (50ft+) on rocks and in coral rubble.

Peristernia chlorostoma; Green Mouthed Spindle; up to 3/4 inch; shallow water to 10ft in coral rubble.

Harpa major var conoidalis; sand and mud bottoms from 20-60 ft; typically seen around dusk when they come out to prey on unsuspecting crab and shrimp.

The Harp shells are amazing creatures. These bad boys are the terror of the sand flats. They live on crabs and shrimp which they envelope with their strong foot and smother with mucous, clogging the gills, and suck dry of life. When prey turns pursuer, the harp is capable of slicing off part of its foot which then placates the hungry pursuing crab while the harp typically escapes into the sand or, ironically enough, counter attacks. While the crab happily munches on the seemingly free meal, the harp will sometimes return to smother the happily feasting crab in mucous and sand, turning its former pursuer into its next meal.

Cypraea (Erosaria) caputserpentis caputophidii, the Snake's Head Cowrie, shown here in a tidy tide pool on a shallow reef flat at low tide. After some years of scarcity, these are starting to become more common again in accessible areas, probably due to some decline in people actively shelling for them.

Grape Drupe, Morula uva, on a shallow tidal flat in the splash zone. These are probably the most common of the Hawaiian drupes and are an attractive white with geometrically placed black spines when cleaned of the coraline algae (or when viewed from below - not shown).

Granulate Drupe, Morula granulata, on a shallow tidal flat in the splash zone. These are found less frequently than the Grape Drupe but frequent the same habitat. These can be differentiated from the Grape Drupe by their near solid black color and more rounded spines (when cleaned of coraline algae or viewed from below - not shown).

Conus ebraeus, a common cone on shallow reef flats, here shown on a reef on Kauai. Photo by Paul Tuskes.

Conus flavidus, typically found on sand on reef flats from 2-10 feet, here shown on a reef on Kauai. Photo by Paul Tuskes.

Conus abbreviatus, intertidal to 20 feet, shown here in Kona. Photo courtesy of Paul Tuskes. These used to be really plentiful in the tide pools in the splash zone.

Drupa morum and Purpura aperata, Kona. Photo courtesy of Paul Tuskes.

A group of Shingle or Helmet urchins, Colobocentrotus atratus. These are called Ha 'uke 'uke in Hawaiian and, while edible,are not commercially harvested. They are usually found out of water in the splash zone clinging to large rocks. Also shown, Entomacrodus marmoratus or the Marbled Blenny.

Slate Pencil Urchin or Heterocentrotus mammillatus can be found on shallow Hawaiian Reef flats.

Echinometra oblonga or Black Rock-Boring Urchin on a shallow reef flat at low tide. As you can see from the sizeable hole this little urchin has drilled, it is aptly named.

Blue-Black Urchin, Echinothrix diadema, or Wana in Hawaiian. These are often found on shallow, exposed reef flats exposed to waves. These little, edible urchins have venomous spines that can hazard the unwary reef-walker.

Charonia tritonis, intertidal to 130 ft., shown here in 10 miles South of Kona, Hawaii. Photo courtesy of Paul Tuskes.

Charonia Tritonis, shown here in 10 miles South of Kona, Hawaii. Photo Courtesy of Paul Tuskes.

I would like to extend my thanks to Stephen Quirk and Betsy Harrison for the information provided in the book Hawaiian Seashells, to Mike Severns for the more exhaustive compilation in the newer text, Hawaiian Seashells and other contributors to this page. My apologies for the occasionally fuzzy photos, most taken one Saturday afternoon spent with the digicam under natural light. If you would like to contribute to additional photos or information to this page, please send me your comments, photos, etc...